Gun-sight telescope.



No.- 856,520. PATENTED JUNE 11, 1907.

E. DNITZ.

GUN SIGHT TELESCOPE. APPLIUATION FILED DEG. 14, 1904.

Unire ,srarnsfrarrmr orrioi.

EMIL DNITZ, OF JENA, GERMANY, ASSIGNOR TO THE FIRM OF CARL ZEISS,

' OF JENA, GERMANY.

GUN-SIGHT TELESGOPE.

Specification. of Letters Patent.

Patented June 11, 1907.

n.pplication filed December 14,1864. Serial No. 236,836.

g ful Improvement in Gun-Sight Telescopes, of

' which the followin is a specification.

Telescopes in wnich the reversed image produced by the objective is erected by a system of prisms instead of by a system of lenses 1o are manifestly, because of their large fields of View, peculiarly appropriate for. the sights of guns, whether such .be small arms or ,ord-

nance. But such gun sight telescopes as heretofore constructed have proved obj eci tionable because the optical axis, that is the line of sight at zero deiection, does not remain invariable. This has been true because the various prisma-tic systems which have heretofore been used in gun sight telescopes 2c consist each of at ieast two prisms separated from cach other either by an air space or by cement. Since it is well known, in this art, that there is no known cement which fuliils the optical requirements and at the same time z5 hardens completely, it has been. necessary in all cases to firmly secure each of the prisms of a system separately in the prism casing. In this way cach of the separate prisms is liable to an accidental rotary displacement, within 3o the prism casing, of substantially the same amount, and when both prisms are displaced the accidental deflections of the line ci sight roduced thereby may reinforce each other. vany attempts have therefore been made to more firmly secure the separate prisms ci gun-sight telescopes Within their casings in.

an immovable manner, a problem which liasbeen rendered diiicult by the change in their refractive condition which is brought about 4o Vby any deformation caused by undue pressure upon the prisms. No satisfactory solution of this problem has as yet been found.

NOW I have produced a gun-sight telescope which avoids these objections by using there- 4 5 in a singlepiece image-erecting prism. l

may say that while such single-piece imagcy erectingprismsare known in the art, they have not as yet found a practical application therein; and it must be distinctly understood 5o that they cannot be built by adopting the arrangement of reflecting surfaces obtained by the iuxtaposition of the parts of a multiprisfiisystem. On the contrary they have an arrangement of reflecting surfaces peculiarly their own, the optical reason for which Vit is unnecessary here to recite.

By an examination Vof the question from an optical and not as 1t might bc imagined from a geometrical standpoint, mere geometrical considerations having no application to the.

problem inl hand, I have discovered that the size of a single-piece image-erecting prism necessarily exceeds that of each component of the multiiece image-erecting prism systems. It fol ows therefrom that by the use of such single-piece prism in gun-sight telescopes, where the danger from displacement due to shocks is peculiarly great, I attain the following advantages: The accidental angular deflection of the line of sight, due to shocks and consequent displacement of the prism in its frame, is but a fraction of that due to any of the parts of a multi-piece prism. The same remark also applies to the maximum angular accidental deflection. Finally the probability of any accidental deflection is but half of that existing in the case of a two-piece prism.

In the dia\vings,-Figure l is an elevation of a sight embodying my invention applied to a rifle, the cover being removed from the prism case. y'Fig'.2 is a plan View of a sight, embodying my invention, applied to a piece of ordnance, the cover of thc prism case being removed.

In Fig. l., yI have shown a frame carrying my sightingtclescopes which is adapted for attachi'ncnt to the riile. This frame comprises a curved arm 1 to which is firmly scoured thc prism case 2 carrying thc objective (i and thc astronomical eye-piece b fitted with a reticulc b. Since thcsinglc-piece imagocrccting prism c may bc securely lodged within the prism caso, it will bc sccn that thc frame rigidly supports the prism. T hc path of a ray of light is shown` by a broken linc passing through the objective, thc prism and thc oye-piece and this makes sufficiently plain, for 'those skilled in thc art, the character of thc prism.

In F ig. 2 thc prism case 2, carrying the objective c, the astronomical oye-piece b, and

containing the single-piece image-erectingprism d, is mounted on a dial base by which arrangement the parts may be secured in a rotatable manner to the head of an ordnance sighting attachment.

In cach iigurc, the prisms arc shown with a .lOO

so-called roof, that is to say a combination oi' two reflecting surfaces, as will be readily understood from other rie-erecting' 'prismatic fsystems. I f

I claim, A l 1. uThe combination of a gn and a sight-- ing telescope comprising an objective', a sin-t gle-piece image-erecting prism and an astronomical eye-piece alll of which liefin' the pth ol" the rsysnromv the targetto. the eye, subthe target pass in the order named, substantialls described.

3. T helcomhilmtion of a gun and :iframe inclosing anll rigidly supporting n singlepiece image-erecting prism, a'n objective, an astronomical eye-piece, und ai reticule, all of which lie in the path of .the rays from the targetto theneyeysubstantially ns described.

In' testimony whereof I have signed my name to thisspeciicntion in the presence of vtwo subscribing witnesses.

EMIL Dt'ixi'rz.

VVitnesses'z,

Pam, KRGER,

Fic'i'rz SANDER. 

